Converter Down

[frizfreleng]

First post, Hello! Parallax Series 7300. 2004 Keystone Cougar 5th Wheel. I leave it plugged into the power pedestal on my property. There is 110 vac at the plug. We just went through a 2 day rain storm. Went to the trailer yesterday and the converter fan was not running. No AC power in the trailer. At least the lights don't work. I didn't try anything else. Water on the kitchen counter above the converter. Don't know if the two are related yet but looks suspicious. Can't believe the converter is flat mounted on the deck but if flooding exists that would explain it. Multi-meter shows 46 vac coming out of the converter. Pretty obvious I am going to have to pull the converter to check it out and find the source of the flooding. I guess I am asking for any sage advice or experience with converter problems.

Thanks, Friz

[MEXICOWANDERER]

A power relay in the low voltage side with a coil diode bias will stop polarity reversal damage to-the-converter, in it's tracks. It would NOT stop damage to devices not connected to the relay.

[BFL13]

Thanks for the follow up so we know what it was.

[MEXICOWANDERER]

Usually a compromised rectifier is needed to blow DC components on a board -- such as a filter capacitor. I slather on dielectric silicone grease to keep the salt air at bay. Florida in the south is as hostile to electrical as deep south Pacific coast Mexico.

[frizfreleng]

End of the story. Finally turned out to be the bus bars (3) in the junction box. Corroded after years of moisture intrusion. I am surprised the 240v to the well pump wasn't lost. If it had been I would have jumped on the problem far sooner. Instead I was off on a wild goose chase in the camper. What I did lose was the 120v to the gate, 120v to the RV receptacle and 120v to an auxiliary plug. Anyhow, replaced the bus bars and put a small barrel over the junction box. Everything works 4.0. Sincerely appreciate all the help!

[MrWizard]

'ripple' is ac leaking into the dc
its not a flat even voltage, it has high points going above the set DC voltage

in many cases that is the fault of a blown 'filter capacitor'

thats what a filter cap is for, to remove/smooth out the ripple coming from the Dc rectifier

[riven1950]

I don't know a lot about converters but ours went out recently on our new 2019 TT. It caused a "ripple" in the DC and knocked out the boards on both the frig and HWH. I had never heard of a ripple before and still don't understand it, but it is a real possibility.





i dont

[wa8yxm]

BFL13 wrote:

pianotuna wrote:
Hi BFL13,

My brothers converter died (not sure of make) It was outputting 114 volts AC.

Where from? How can you get AC on the DC side? I have heard of "ripple" but not sure what that is exactly.

In the old days converters (Magnetek 6300 for example) used a big heavy iron core transformer and it would take quite a bunch to get 120 vac past it. However today many converters are "Switching power supplies" and ... Well it can happen.

As for getting AC out of a DC supply. that's very easy. takes one part failure. that's all. the filter cap.

[drsteve]

BFL13 wrote:
Don't know exactly which ones, but ISTR some 120v things will be ruined if you turn them on with real low voltage like you see now at your home pedestal after that rain.

So IMO, don't plug the cable in and turn things on until after you see 120v at the repaired pedestal. Good news the rig is ok for your trip.

Low voltage can overheat and ruin an AC or residential fridge compressor. Not kind to the microwave either...

[BFL13]

Don't know exactly which ones, but ISTR some 120v things will be ruined if you turn them on with real low voltage like you see now at your home pedestal after that rain.

So IMO, don't plug the cable in and turn things on until after you see 120v at the repaired pedestal. Good news the rig is ok for your trip.

[frizfreleng]

BFL13 wrote:
" That wasn't 42 VAC out of the converter! That was 42 VAC at the cable end going into the converter."

Not understood. The 120v to the 7300 is not from a "cable" The converter input is a black wire and a white wire. the black goes to the bottom of a 120v circuit breaker above that on the AC panel, while the white wire goes over to the neutral buss with the other branch neutrals.

Where exactly did you have the two meter probes when seeing that 42 volts? Also does anything else 120v work, like the microwave, things plugged into the 120v receptacles?

The cable or cord I refer to is the black shore power cable I pull out of the back of the back of the 5th wheel and plug into shore power. The cable does terminate at and connect to the converter AC input.
Once again sorry for the confusion about saying it was "42 vac out of the converter" when I meant "in". I measured 42 vac, with the black (hot) cable wire disconnected from the converter and ground. Also measured 42 vac between the disconnected black wire and the white (neutral). Did not try the microwave, fridge or outlets. As I said, I connected the male plug end of the cable to an independent 120 vac source and the converter fan started and the 120 vac lights came on. Now looking at a pedestal problem but no roof leak problem (thank God).
P.S. the water on the counter was from an open window (duh). It had nothing to do with the converter shutdown.

[BFL13]

" That wasn't 42 VAC out of the converter! That was 42 VAC at the cable end going into the converter."

Not understood. The 120v to the 7300 is not from a "cable" The converter input is a black wire and a white wire. the black goes to the bottom of a 120v circuit breaker above that on the AC panel, while the white wire goes over to the neutral buss with the other branch neutrals.

Where exactly did you have the two meter probes when seeing that 42 volts? Also does anything else 120v work, like the microwave, things plugged into the 120v receptacles?

[frizfreleng]

wa8yxm wrote:
Prallex 7300 is a single stage (13.6 volt) converter not really very good. Suggest replace the "Works" with a Progressive Dynamics 4600 3-stage + converter.

HOwever water on the counter.. Doubt it was from flooding on the floor. more likely a leaking kitchen window.

The parallex 7300 has 3 major modules

120 volt breaker panel.. This accepts 120vac from teh shore cord (If you are wired for a generator it may come in via a transfer switch) IF you have water where you shoudl not have water good chance a GFCI back at the house it tripped. Plug something into the socket the RV is plugged into to verify it is live.

THe breaker panel then Distributes power to the RV's 120 volt stuff. A/C's AC side of fridge and water heater. Entainerment electronics Kitchen and bath and patio and the CONVERTER module This converts 120vac to 13.6 VDC and feeds the batteries and the 12 volt FUSE panel/distribution panel which then feeds the lights and water pump, furnmace AC, Fridge, Water heater control boards and fans.

The voltage you show coming OUT of the converter??? I'd like to know how you got that. It indicates eitehr a MAJOR failure. A bad meter or bad meter lead placement.. IT is well above the maximum theoretical voltage which is a bit under 20.

Good call! The window above the sink was cranked open (duh). By the way, my mistake, that wasn't 42 VAC out of the converter! That was 42 VAC at the cable end going into the converter from the power pedestal. You are right, it would be a major failure. All DC is functioning normally: lights, pump, monitor panel.
Although your suggestion of a new Progressive Dynamics is appealing, if the old Parallax is still working I am going to stay with it. When the time comes I will take you up on your suggestion. Thank you.

[wa8yxm]

Prallex 7300 is a single stage (13.6 volt) converter not really very good. Suggest replace the "Works" with a Progressive Dynamics 4600 3-stage + converter.

HOwever water on the counter.. Doubt it was from flooding on the floor. more likely a leaking kitchen window.

The parallex 7300 has 3 major modules

120 volt breaker panel.. This accepts 120vac from teh shore cord (If you are wired for a generator it may come in via a transfer switch) IF you have water where you shoudl not have water good chance a GFCI back at the house it tripped. Plug something into the socket the RV is plugged into to verify it is live.

THe breaker panel then Distributes power to the RV's 120 volt stuff. A/C's AC side of fridge and water heater. Entainerment electronics Kitchen and bath and patio and the CONVERTER module This converts 120vac to 13.6 VDC and feeds the batteries and the 12 volt FUSE panel/distribution panel which then feeds the lights and water pump, furnmace AC, Fridge, Water heater control boards and fans.

The voltage you show coming OUT of the converter??? I'd like to know how you got that. It indicates eitehr a MAJOR failure. A bad meter or bad meter lead placement.. IT is well above the maximum theoretical voltage which is a bit under 20.

[frizfreleng]

Okay I got to the bottom of it. I wired an independent 120vac source to the male cable end and the converter came on!
The fan started blowing and a couple of 120vac lights came on. Converter is a couple of inches off the deck and no evidence of water around. The puddle on the counter was just coincidence and now I don't believe it had anything to do with the converter problem. Now I have to work on the power pedestal and fix a roof leak. All the 12 vdc lights worked find after I turned on the 4 rocker switches at the door (duh).

Thanks for all the help.

Friz

P.S. the water on the counter was from an open window duh). Nothing to do with the converter shutdown.